Inherently-shielded cable construction with a braided reinforcing and grounding layer

• US 5,262,591 A
• Filed: 06/19/1992
• Issued: 11/16/1993
• Est. Priority Date: 08/21/1991
• Status: Expired due to Fees

• Current Assignee: Champlain Cable Corporation (Brown & Brown Inc.), The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: Champlain Cable Corporation (Brown & Brown Inc.)
• Inventors: Aldissi, Mahmoud
• Primary Examiner(s): NIMMO, MORRIS
• Application Number:
  US07/901,291
• Time in Patent Office: 515 Days
• Field of Search: 174/36, 174/34, 174/102 SC, 174/106 SC, 252/513
• US Class Current: 174/36
• CPC Class Codes: C08K 3/24 Acids; Salts thereof C08K3/16 takes precedence
• CPC Class Codes: C08L 27/12 containing fluorine atoms
• CPC Class Codes: H01B 11/1083 the coating containing magnetic material
• CPC Class Codes: H01F 1/26 by macromolecular organic substances

Abstract

The present invention features a new "filter line" cable of very thin construction. The thinner cable has a reinforcing mesh layer that lends physical strength to the otherwise thinner, weakened cable. Additionally, the reinforcing mesh provides grounding and some shielding. The reinforcing mesh layer is made of a thin metal wire or metal-coated fibers. The filter line cable has a conductive core having a primary insulation layer. Over the primary insulation is a filtering layer made up of metal-coated ferromagnetic particles of ferrite or magnetite dispersed within a polymeric matrix such as Viton, a fluorinated elastomeric polymer. The ferromagnetic particles may be "spherical", to enhance the filtering effect. The filtering layer provides the "filter line" protection against internal RFI and microwave interferences traveling down the wire. Over the filtering layer is a layer of metal wire or metal-coated fibers, woven or served into a mesh. This layer shields the filtering layer and provides protection against external EMI signals. The reinforcing mesh layer is lightweight and provides a minimum of shielding coverage, i.e., approximately between 15 to 50% of the filter line layer; its primary purpose is to provide physical reinforcement and grounding.

Claims

1. An ultra-thin filter line cable having a reinforcing mesh and grounding layer disposed over a filter layer, comprising:

a conductive core;

a primary insulation layer disposed over said conductive core;

a filter line layer disposed over said primary insulation layer including metal-coated ferromagnetic particles disposed in a polymer matrix, said filter line layer having a thickness of approximately between 3 to 5 mils;

a reinforcing and grounding layer disposed over said filter line layer, said reinforcing and grounding layer comprising a conductive mesh and providing approximately between 15-50% coverage of said filter line layer, said reinforcing and grounding layer enhancing cable shielding, providing physical strengthening of the ultra-thin cable, and providing grounding; and

a jacket of at least one layer disposed over said reinforcing layer.

2. The ultra-thin filter line cable of claim 1, wherein said metal-coated ferromagnetic particles further comprise particles selected from a group of materials consisting of metal-coated ferrite, metal-coated magnetite and combinations thereof.

3. The ultra-thin filter line cable of claim 1, wherein said metal-coated ferromagnetic particles are coated with a metal selected from a group consisting of silver, nickel, copper, zinc and manganese.

4. The ultra-thin filter line cable of claim 2, wherein said metal-coated ferromagnetic particles are comprised of "spherical" particles.

5. The ultra-thin filter line cable of claim 1, wherein said jacket comprises at least one layer of material selected from a group of materials consisting of fluorinated polyethylene, carbon-filled fluorinated polyethylene, polytetrafluoroethylene polytetrafluoroethylene fused with polyimide.

6. The ultra-thin filter line cable of claim 5, wherein said jacket comprises two fused layers comprising polytetrafluoroethylene and polyimide.

7. The ultra-thin filter line cable of claim 1, wherein said jacket comprises three fused layers comprising polytetrafluoroethylene, polyimide and polytetrafluoroethylene.

8. The ultra-thin filter line cable of claim 1, wherein the wire of said mesh of said reinforcing and grounding layer comprises metal or metal-alloy.

9. The ultra-thin filter line cable of claim 8 wherein said metal or metal-alloy comprises silver, coated on said wire of said mesh.

10. The ultra-thin filter line cable of claim 1 wherein said conductive mesh comprises metal-coated fiber strands.

11. An ultra-thin filter line cable having a reinforcing and grounding layer disposed over a filter line layer, comprising:

a conductive core;

a primary insulation layer disposed over said conductive core;

a filter line layer disposed over said primary insulation layer including spherical, silver-coated ferromagnetic particles disposed in an elastomeric polymer matrix, said filter layer having a thickness of approximately between 3 and 5 mils;

a reinforcing and grounding layer disposed over said filter line layer, said reinforcing and grounding layer comprising a mesh of conductive wire or fiber strands, and providing approximately between 15-50% coverage of said filter line layer, said reinforcing and grounding layer enhancing shielding and providing physical strengthening and grounding of the ultra-thin filter line cable; and

a jacket of at least one layer disposed over said shield layer.

12. The ultra-thin filter line cable of claim 11, wherein said silver-coated ferromagnetic particles further comprise particles selected from a group of materials consisting of metal-coated ferrite, metal-coated magnetite and combinations thereof.

13. The filter line cable of claim 12, wherein said metal-coated ferromagnetic particles are blended with metal particles.

14. The filter line cable of claim 11, wherein said elastomeric polymer matrix comprises a fluorinated elastomer.

15. The filter line cable of claim 11, wherein said jacket comprises at least one layer of material selected from a group of materials consisting of fluorinated polyethylene, carbon-filled fluorinated polyethylene, polytetrafluoroethylene and polytetrafluoroethylene fused with polyimide.

16. The ultra-thin filter line cable of claim 11, wherein said metal-coated ferromagnetic particles are comprised of "spherical" particles.

17. The filter line cable of claim 15, wherein said jacket comprises two fused layers comprising polytetrafluoroethylene and polyimide.

18. The filter line cable of claim 15, wherein said jacket comprises three fused layers comprising polytetrafluoroethylene, polyimide and polytetrafluoroethylene.